Texturing yarns by false twisting

ABSTRACT

Untextured yarn is drawn from a producer&#39;&#39;s package, threaded through apparatus comprising a tension leveling device, an electric heater and a false twist device and, having been textured thereby, is wound on yarn take-up means. Close to the yarn exit from the heater is a twist stop device which effectively restricts twisting of the yarn to the downstream side thereof, and close to the downstream side of the false twist device is a check device which effectively restricts to the downstream side thereof the tendency of the yarn to relax due to untwisting thereof.

United States Patent [191 Spurgeon Jan. 1, 1974 [54] TEXTURING YARNS BYFALSE TWISTING 3,626,682 l2/l97l Spurgeon 57/773 [76] Inventor: RichardC. Spurgeon, R.D. No. 2,

Lansdale' p 1944 Primary Examiner-John Petrakes AssistantExaminer-Charles Gorenstein [22] filed: 1972 Attorney-Louis V. Schiavo[21] App]. No.: 223,227

[57] ABSTRACT [52] US. Cl 57/34 HS, 57/77.4, 57/106, Umexmred yam isdrawn from a producer's package,

57/157 TS threaded through apparatus comprising a tension lev- [5 Dozg1/02' Dolh 13/08 Dozg H08 eling device, an electric heater and a falsetwist device [58] Field ofSearch ..57/77.377.45, 106, 34 HS, and havingbeen textured thereby, is wound on yam m is -5 isvill 5. S take-upmeans. Close to the yarn exit from the heater is a twist stop devicewhich effectively restricts twist- [56] References cued ing of the yarnto the downstream side thereof, and UNITED STATES PATENTS close to thedownstream side of the false twist device 1,216,147 2/1917 is a checkdevice which effectively restricts to the 2,738,634 4/1957 downstreamside thereof the tendency of the yarn to 2,977,745 4/1961 relax due tountwisting thereof. 3,043,084 7/l962 3,444,683 5/1969 Hcsscnbruch 57/106X 6 Claims, 5 Drawing Figures 52? 12 i so 15 a a; 345 42 '5 g 40 .6 .856 1' j 4O 42 rl l e I g, h a 4 P7: T T l h Y a l l :1: I l l 111 I I II 1 g 1 I r I I i l I PATENIED JAN 1 "H4 POINT AT WHICH YARN ISSUES FROMHEATER O 7 flm J w M l H 0 WW V m R W m M F w m o M M w H s N s R L 4 MN A M 5 II R Y T O A D O P Y m E T T W n S W R X 4 W N Y 2 m m m o m Y nE h 1, 3 Q A T P g W mm w wx E w m w fl/w M T J m E N w nvA X M Y.\ m mD. J 1M G n g W I m S 9 G R D T M Q 1 M 4m F s M 4 i F M .AIUBM W Y u 4m WY w P w BACKGROUND OF THE INVENTION 1. Field of the Invention Thepresent invention relates to the texturing of yarn by false twisting,and particularly to improvement of the method and apparatus disclosed inmy pending application for U.S. Letters Patent, Ser. No. 168,709, filedAug. 3, 1971.

2. Description of the Prior Art As taught by said pending application,the yarn passing over the edges of the twist stop plate is notrestrained against rolling along said edges in response to twisting ofthe yarn. Accordingly, tension in the yarn may vary, resulting in acertain degree of non-uniform texturing in the resulting yarn.

SUMMARY OF THE INVENTION The principal object of the present inventionis to provide improved apparatus and method for texturing continuousfilament thermoplastic yarn by false twisting.

Another object of the present invention is to provide such apparatus andmethod whereby tight control of the yarn is exercised to preventdisplacement thereof from a predetermined yarn path as the yarn twistingeffort applied approaches a maximum.

BRIEF DESCRIPTION OF THE DRAWINGS:

FIG. 1 is an elevation showing apparatus constructed in accordance withthe present invention;

FIG. 2 is a section on lines ll-ll in FIG. 1;

FIG. 3 is an enlarged view on lines Ill-III in FIG. 2;

FIG. 4 is an enlarged section on lines II-II showing an alternatearrangement; and

FIG. 5 is an enlarged section on lines "-11 showing another alternatearrangement.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring particularly to FIGS.1 and 2, the apparatus shown includes a tension leveling device 10, anelectric heater 12, a twist stop device 14, yarn guide means 15, a falsetwist device 16, and a check device 18.

The tension leveling device includes a roller 20. To the left of theroller is a standard 22 embraced by a ring 24 and provided with aneyelet 26 at the head thereof, and to the right of the roller 20 is asecond standard 28 embraced by a ring 30 and provided with an eyelet 32at the head thereof. Reference may be had to my U.S. Pat. No. 3,323,753,issued June 6, 1967, for the essential features of the tension levelingdevice and for the principle of its operation.

The electric heater 12 includes a main body 34 which accommodates aheating coil 56. A pair of grooves respectively on opposite sides of themain body 34 are covered by plates 40, and extending about the heater isa jacket 42 of insulating material. The bottom of the heater carries aplate 44 which mounts a pair of eyelets 46 and 48 respectively alignedwith said grooves, and the top of the heater carries a plate 50 whichmounts a pair of eyelets 52 and 54 also respectively aligned with saidgrooves.

The bottom of the heater also carries a plate 60 to which is affixed thetwist stop device 14 in the form of a plate provided with square edges64.

The false twist device 16 includes a rubber rimmed friction disc 66actuated by an electric motor 68, and

the check device 18 includes a rubber rimmed friction disc 70 actuatedby an electric motor 72. For holding the yarn to the rims of the discs66 and 70 a frame 74 is provided with arms which mount eyelets 82, 84and 86. Reference may be had to my pending application for US. LettersPat., Ser. No., 168,709, filed Aug. 3, 1971, for the essential featuresof the electric heater 12, the twist stop device 14, the false twistdevice 16 and the check device 18, and for the principles of theiroperation.

An end of untextured multifilament yarn, designated Y, is drawn from ayarn package (not shown) and threaded through the eyelet 26, passeddownwardly along the standard 22 and threaded through the ring 24. Thenit is passed under the roller 20 in contact therewith, threaded throughthe ring 30, passed upwardly along the standard 28 and threaded throughthe eyelet 32. Then the yarn end is looped through the heater 12, beingpassed upwardly through the eyelets 46 and 52 and then downwardlythrough the eyelets 54 and 48. When the yarn end issues from the eyelet48, it is turned sharply to one side and trained along the upper surfaceof the stop twist plate 14, about the edges 64 thereof, fully in contacttherewith, and along the undersurface of the stop twist plate 14. Thenthe yarn end is trained about the yarn guide means 15. At the falsetwist device, the yarn end is passed through the eyelets 82, 84 and 86,which are positioned to bring the yarn end into contact with the rim ofthe friction disc 66 of the false twist device and the rim of thefriction disc 70 of the check device, as shown. From the eyelet 86, theyarn end goes to a yarn take-up means, which may be in the form of aconventional ring and traveler array (not shown).

The roller 20 turns in yarn advancing direction at a speed which exceedsthe linear speed of the yarn end. Tension in the yarn is inducedbyresistance to movement of the yarn over the edges 64 of the twist stopplate 14. The yarn between the tension leveling device 10 and the yarntake-up means will be predetermined in length for a desired yarntension. When said length increases, the rings 24 and 30 are lowered,removing some of the yarn from engagement with the roller 20 andincreasing slippage between the roller 20 and the yarn end. Thus theamount of yarn passing under the roller 20 is reduced and the yarnbetween the tension leveling device and the yarn take-up means isrestored to its initial length. When said length decreases, the rings 24and 30 are raised, causing a greater length of yarn to engage the roller20 and decreasing slippage between the roller 20 and the yarn end. Thusthe amount of yarn passing under the roller 20 is increased and thelength of yarn between the tension leveling device and the yarn take-upmeans is restored to its initial length.

In view of the foregoing, it will be appreciated that insofar as thetension leveling device 10, the heater l2 and the twist stop device 14are concerned, the apparatus is identical in construction and operationto that disclosed in my pending application, Ser. No. 168,709, filedAug. 3, 197i, to which reference may be had for further details ofconstruction and principles of operation. The critical difference in themanner of operation of the apparatus resulting from introduction of theyarn guide means 15 will now be pointed out.

As taught by my pending application for US. Letters Pat. Ser. No.168,709, filed Aug. 3, 1971, the portion of the yarn path at the twiststop plate is substantially in the form of a square loop the whole ofwhich is disposed in a plane normal to the edges of the twist stop plateover which the yarn is drawn. When the degree of twist is not in excessof approximately 200 turns per inch, this arrangement may besatisfactory, but when the degree of twist is higher, the arrangement isnot entirely satisfactory because the highly twisted yarn tends to rollalong the edges of the twist stop plate in one direction or the other inresponse to the applied twisting effort.

The tension in the twisted yarn downstream from the edges of the twiststop plate is greater than the tension in the untwisted yarn upstreamfrom the edges of the twist stop plate, and the function of the deviceis to level each yarn tension, i.e., keep each of them within acceptablelimits. Accordingly, yarn tension varies somewhat within predeterminedmaximum and minimum limits. As a consequence of the tension in thetwisted yarn area being greater than the tension in the untwisted yarnarea, there is a constant tendency for tension in the twisted yarn areato escape upstream into the untwisted yarn area, and this tendencyincreases as the degree of twist and the resulting yarn tensionincrease. Periodically, when the degree of twist and the resulting yarntension are at a maximum and the yarn has rolled along the edges of thetwist stop plate in one direction or the other in response to theapplied twisting effort, tension does in fact escape, whereupon the yarnsnaps back to its initial position. This periodic escape of tensionupstream from the twisted yarn area into the untwisted yarn area causesa certain degree of non-uniform texturing in the resulting yarn, whichmay be avoided by restraining the yarn against rolling along the edgesof the twist stop plate in response to the applied twisting effort. Thismay be accomplished in several ways.

Referring particularly to FIGS. 1 and 2, the yarn guide means comprisesa base member 100 stationarily mounting an upright rod 102 which iscircular in transverse section, and which is thereby disposed betweenthe twist stop device 14 and the false twist device 16 and to one sideof a direct line therebetween. The yarn extending from the twist stopdevice 14 to the false twist device 16 is trained about the rod 102 forguidance. Referring particularly to FIGS. 1, 2 and 3, it will be notedthat the portion of the yarn path at the twist stop plate 14 is in theform of a square loop, and referring particularly to FIG. 2, it will benoted that the opposed arms of the loop are disposed on opposite sidesof a reference plane X--X containing the closed end of theloop anddisposed approximately normal to 5 the edges of the twist stop plate 14over which the yarn is drawn, and that the angles A included between thearms of the loop and the plane of reference XX are substantially equal.Yarn trained about the twist stop plate 14 and the rod 102 as shown willnot roll along the edges 64 of the twist stop plate 14 in response tothe applied twisting effort. To the contrary, training the yarn aboutthe rod 102 has the effect of restricting the yarn to movement along apredetermined fixed path, as a consequence of which repeating cycleswherein yarn tension increases from a predetermined minimum to apredetermined maximum and then suddenly and abruptly escape from thetwisted yarn area upstream into the untwisted yarn area is effectivelyavoided.

While, in accordance with the provisions of the patent statutes, I haveillustrated and described the best embodiment of my invention now knownto me, it will be apparent to those skilled in the art that changes maybe made without departing from the scope of the invention as set forthin the appended claims. For example,

referring particularly to FIG. 4, in lieu of the yarn guide means 15,the twist stop plate 14 may mount a yarn guide pin 104 extendingrearwardly therefrom on one side or the other of the yarn path,depending upon the direction in which the yarn is twisted; and referringparticularly to FIG. 5, in lieu of the yarn guide means 15, the twiststop plate 14 may be provided wtih a narrow yarn guide groove 106through which the yarn may pass freely.

I claim:

1. The combination comprising A. a source of yarn,

B. a utility operable at least periodically for continuously drawingyarn from said source,

C. a member provided with a pair of edges,

D. means for training said yarn over said edges for movement thereof ina substantially square loop having sections providing opposed laterallyspaced arms of said loop and a section interconnecting said arms andproviding a closed end of said loop, the arms of said loop beingdisposed on opposite sides of a reference plane containing the closedend of said loop and disposed approximately normal to the edges of saidedged member,

E. tension leveling means between said yarn source and edged member,said edged member responsive to a predetermined yarn length between saidtension leveling means and utility for developing resistance to movementof said yarn over said edged member whereby to induce a predeterminedtension in the yarn on the downstream side of said edged member, saidtension leveling means being operative for maintaining the length ofyarn between said tension leveling means and utility uniform,

F. a heater interposed between said tension leveling device and edgedmember and operable for heating the yarn to a temperature sufficient toplasticize but insufficient to melt said yarn,

G. means interposed between said edged member and utility for twistingthe yarn, and

H. means for restraining the yarn against rolling along the edges ofsaid edged member in response to the twisting effort applied thereto.

2. The combination according to claim 1 wherein the angles includedrespectively between the opposed arms of the loop and the plane ofreference are substantially equal.

3. The combination according to claim 2 wherein the yarn restrainingmeans includes yarn guide means fixed in the yarn path and therebydisposed a substantial distance downstream from the closed end of theloop and a substantial distance from the reference plane for withdrawalof said yarn from the closed end of the loop and away from saidreference plane to said yarn guide means, around the latter and thenaway from said yarn guide means and back toward said reference plane tosaid yarn twisting means.

4. The combination according to claim 3 wherein the downstream one ofsaid arms extending from the closed end of said loop outwardly away fromsaid reference plane and then back inwardly towards said referenceplane, B. drawing continuous filament thermoplastic yarn from a sourcethereof along said path to a utility, C. restraining said yarn to inducepredetermined tension in the same when a predetermined length thereofextends from said utility to a location upstream from said loop,

D. compensating for variations in the length of the yarn extending fromsaid utility to said location whereby to maintain the same uniform,

E. heating the yarn in the portion of the yarn path upstream from saidloop to a temperature sufficient to plasticize but insufficient to meltsaid yam,

F. applying a twisting effort to said yarn at a point downstream fromthe closed end of said loop and thereby turning said yarn about its axiswhereby to twist in one direction the portion thereof extending upstreamfrom said point to the closed end of said loop, and whereby to turn inthe opposite direction the portion thereof extending downstream fromsaid point to said utility, and

G. restraining said yarn to secure the portion thereof which is in theform of a substantially square loop against displacement from apredetermined yarn path in response to the applied twisting effort. l

' Attesting Officer UNITED STATES PATENT OFFICE CERTIFICATE OFCORRECTION Patent NO. 3,782,091 Dat d JANUARY 1, v

Inventofls) RICHARD C SPURGE ON It is certified that errorappears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

7 COLUMN 4, CLAIM 1, Line 2, under paragraph E, after "member" andbefore "re sponsive" insert --being-'-.

Signed and sealer i: this, ,llth day of June 197 (SEAL) Attest:

c. MARSHALL 1mm f a Commissioner of Patents EDJARD. ummz'rcnam, .m.

1. The combination comprising A. a source of yarn, B. a utility operableat least periodically for continuously drawing yarn from said source, C.a member provided with a pair of edges, D. means for training said yarnover said edges for movement thereof in a substantially square loophaving sections providing opposed laterally spaced arms of said loop anda section interconnecting said arms and providing a closed end of saidloop, the arms of said loop being disposed on opposite sides of areference plane containing the closed end of said loop and disposedapproximately normal to the edges of said edged member, E. tensionleveling means between said yarn source and edged member, said edgedmember responsive to a predetermined yarn length between said tensionleveling means and utility for developing resistance to movement of saidyarn over said edged member whereby to induce a predetermined tension inthe yarn on the downstream side of said edged member, said tensionleveling means being operative for maintaining the length of yarnbetween said tension leveling means and utility uniform, F. a heaterinterposed between said tension leveling device and edged member andoperable for heating the yarn to a temperature sufficient to plasticizebut insufficient to melt said yarn, G. means interposed between saidedged member and utility for twisting the yarn, and H. means forrestraining the yarn against rolling along the edges of said edgedmember in response to the twisting effort applied thereto.
 2. Thecombination according to claim 1 wherein the angles includedrespectively between the opposed arms of the loop and the plane ofreference are substantially equal.
 3. The combination according to claim2 wherein the yarn restraining means includes yarn guide means fixed inthe yarn path and thereby disposed a substantial distance downstreamfrom the closed end of the loop and a substantial distance from thereference plane for withdrawal of said yarn from the closed end of theloop and away from said reference plane to said yarn guide means, aroundthe latter and then away from said yarn guide means and back toward saidreference plane to said yarn twisting means.
 4. The combinationaccording to claim 3 wherein the yarn guide means has a yarn engagingsurface on the side thereof remote from the plane of reference.
 5. Thecombination according to claim 4 wherein the yarn guide means is anelongated member substantially parallel to the closed end of the loop.6. In a method of false twisting a continuous thermoplastic yarn, thesteps comprising A. establishing a yarn path having a portionsubstantially in the form of a square loop having arms disposedrespectively on opposite sides of a reference plane containing theclosed end of said loop, the downstream one of said arms extending fromthe closed end of said loop outwardly away from said reference plane andthen back inwardly towards said reference plane, B. drawing continuousfilament thermoplastic yarn from a source thereof along said path to autility, C. restraining said yarn to induce predetermined tension in thesame when a predetermined length thereof extends from said utility to alocation upstream from said loop, D. compensating for variations in thelength of the yarn extending from said utility to said location wherebyto maintain the same uniform, E. heating the yarn in the portion of theyarn path upstream from said loop to a temperature sufficient toplasticize but insufficient to melt said yarn, F. applying a twistingeffort to said yarn at a point downstream from the closed end of saidloop and thereby turning said yarn about its axis whereby to twist inone direction the portion thereof extending upstream from said pOint tothe closed end of said loop, and whereby to turn in the oppositedirection the portion thereof extending downstream from said point tosaid utility, and G. restraining said yarn to secure the portion thereofwhich is in the form of a substantially square loop against displacementfrom a predetermined yarn path in response to the applied twistingeffort.